HP 8920A Programmer's Manual page 483

Chapter 8, Programming The Call Processing Subsystem
Programming The CALL CONTROL Screen
Release
This field is used to terminate an active voice channel connection with the mobile
station.
When the field is selected, a mobile station control message with a
Release
Release order is sent to the mobile station on the forward voice channel. A mobile
station must be actively connected on a voice channel to the Test Set (that is, the
annunciator lit) before attempting to send a release order to the mobile
Connect
station.
The :RELease command is used to control this field.
There is no query form of the :RELease command.
Syntax
:RELease
Example
OUTPUT 714;"CALLP:REL"
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